29131220 has 12 divisors (see below), whose sum is σ = 61175604. Its totient is φ = 11652480.

The previous prime is 29131187. The next prime is 29131243. The reversal of 29131220 is 2213192.

It can be written as a sum of positive squares in 2 ways, for example, as 16613776 + 12517444 = 4076^2 + 3538^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1456561 = 29131220 / (2 + 9 + 1 + 3 + 1 + 2 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 29131192 and 29131201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 728261 + ... + 728300.

It is an arithmetic number, because the mean of its divisors is an integer number (5097967).

Almost surely, 2^29131220 is an apocalyptic number.

29131220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

29131220 is an abundant number, since it is smaller than the sum of its proper divisors (32044384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

29131220 is a wasteful number, since it uses less digits than its factorization.

29131220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1456570 (or 1456568 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 29131220 is about 5397.3345273385. The cubic root of 29131220 is about 307.6943755310.

The spelling of 29131220 in words is "twenty-nine million, one hundred thirty-one thousand, two hundred twenty".